SPF45-related splicing factor for phytochrome signaling promotes photomorphogenesis by regulating pre-mRNA splicing in Arabidopsis ($)

Light is one of the environmental conditions which regulates plants’ development, but knowledge of how light-induced transcript accumulation occurs via transcriptional versus post-transcriptional mechanisms is limited. Xin et al. report Splicing Factor for Phytochrome Signaling (SFPS) as an interacting partner of the photoreceptor Phytochrome B. The sfps mutant has a hyposensitive response to light and controls pre-mRNA processing of myriad genes involved in light signaling, photosynthesis, and the circadian clock. Additionally, the study of the quadruple pif mutant (pifq) revealed that Phytochrome Interacting Factors (PIFs) work downstream of SFPS. The authors propose a model where light-dependent development is regulated via SFPS, by controlling pre-mRNA processing of light signaling and circadian clock genes. Proc. Natl. Acad. Sci. USA 10.1073/pnas.1706379114